Swath guidance systems are used in applications where equipment must be moved across the surface of the ground or water in a precise path. For example, agricultural equipment for spraying crops would be guided to traverse parallel paths (swaths) of equal width across a field. Swath guidance systems display information to assist the equipment operator in keeping his equipment on the correct swath. For such applications accuracy, update speed and ease of system use are very important.
In the current state of the art, direction error information is typically displayed by a "light bar" which consists of a row of lights which illuminate from the center of the row to the right or to the left to indicate the direction and extent of deviation from the desired swath. Direction error information is derived by an externally located computer from position data received by an external positioning system such as a Global Positioning System (GPS) receiver. Some systems also provide a separate control panel to allow the user to select various options.
Several problems are associated with the current state of the art systems. Such systems are not compact and the user must take his eyes away from the task of driving the equipment in order to set device options or view system indicators other than the light-bar. This creates a safety hazard and also can introduce wasteful navigational deviations. Also, current systems do not provide easy means to specify a desired path from which direction error can be determined.
Thus, a need exists for an apparatus for displaying swath navigation information and guidance system information that is compact, can be mounted within the operative view of the user, and provides easy means for swath specification.